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" Generic " Unbalanced Feistel Schemes with Expanding Functions are Unbalanced Feistel Schemes with truly random internal round functions from n bits to (k−1)n bits with k ≥ 3. From a practical point of view, an interesting property of these schemes is that since n < (k − 1)n and n can be small (8 bits for example), it is often possible to store these truly… (More)

While generic attacks on classical Feistel schemes and unbalanced Feistel schemes have been studied a lot, generic attacks on several generalized Feistel schemes like type-1, type-2 and type-3 and Alternating Feistel schemes, as defined in [6], have not been systematically investigated. This is the aim of this paper. We give our best Known Plaintext Attacks… (More)

In [12] a Zero-Knowledge scheme ZK(2) was designed from a solution of a set of multivariate quadratic equations over a finite field. In this paper we will give two methods to generalize this construction for polynomials of any degree d, i.e. we will design two Zero-Knowledge schemes ZK(d) and˜ZK(d) from a set of polynomial equations of degree d. We will… (More)

There are many kinds of attacks that can be mounted on block ciphers: differential attacks, impossible differential attacks, truncated differential attacks, boomerang attacks. We consider generic differential attacks used as distinguishers for various types of Feistel ciphers: they allow to distinguish a random permutation from a permutation generated by… (More)

A usual way to construct block ciphers is to apply several rounds of a given structure. Many kinds of attacks are mounted against block ciphers. Among them, differential and linear attacks are widely used. In [18, 19], it is shown that ciphers that achieve perfect pairwise decorrelation are secure against linear and differential attacks. It is possible to… (More)

The factorization problem in non-abelian groups is still an open and a difficult problem [12]. The hardness of the problem is illustrated by the moves of the Rubik's cube. We will define a public key identification scheme based on this problem, in the case of the Rubik's cube, when the number of moves is fixed to a given value. Our scheme consists of an… (More)

Since the invention of the Rubik's cube by Ernö Rubik in 1974, similar puzzles have been produced, with various number of faces or stickers. We can use these toys to define several problems in computer science, such as go from one state of the puzzle to another one. In this paper, we will classify some of these problems based on the classic Rubik's cube or… (More)